Among conventional methods for remotely maintaining communication monitoring apparatuses located at remote sites is a software remote maintenance method described in Japanese Patent Application Laid-Open Publication No. 2006-182080. In the software remote maintenance method, a data collection/control network is built up by mutually connecting via intra-network lines the communication monitoring apparatuses separately located at different areas. Each of the communication monitoring apparatuses determines whether a maintenance command input from a maintenance terminal is directed to a remote site or to own site, and if directed to the remote site, adds a destination address and a source address used in the network to the maintenance command, for transmission to the remote communication monitoring apparatus through the intra-network lines.
On the contrary, a transmission network having transmission apparatuses such as cross-connect apparatuses, optical cross-connect apparatuses, etc., in the SONET/SDH (Synchronous Optical Network/Synchronous Digital Hierarchy) system or the WDM (Wavelength Division Multiplexing) system is provided with a network management system (NMS) for entering cross-connects of the transmission apparatuses and entering paths in the transmission network.
With progress of enlargement in scale and capacity of the transmission network, recent years are experiencing introduction of such a hierarchized NMS as represented by a hierarchical model of the TMN (Telecommunication Management Network). This hierarchical model is provided with e.g., an upper network management layer of NMS (NMS-NML) and a lower element management layer of NMS (NMS-EML). The NMS-NML provides a centralized management of the overall transmission network, whereas portions of the transmission network are managed by the NMS-EML managing the portions of the transmission network.
The state of the art allows entering, editing, etc., of the cross-connects to be effected equally by the NMS-NML, the NMS-EML and a local craft terminal (LCT) coupled directly to each of the transmission apparatuses to enter cross-connects of the transmission apparatuses. Therefore, any one of the NMSes and LCTs could fully operate the cross-connect facilities in case that user accounts used have the authority to perform entering, edit, cancellation (deletion), etc., of the cross-connects.
However, when the respective layers of NMSes and LCTs have the same authority to allow free entering, edit, deletion, etc., of the cross-connects in this manner, if adequate communications are not secured between the persons in charge of maintenance using the respective layers, there may possibly arise inconsistencies in entering of the cross-connects to throw the entire system into confusion, resulting in failures such as incorrect transmission of signals.